1. Field of the Invention
The present invention relates to improvements to an intermittent motion type decorating machine for decoration of workpieces and, more particularly, to improving the method and apparatus for decorating workpieces in such a decorating machine by providing that while workpieces are decorated at each of a plurality of decorating stations, the ink decoration applied at one of the decorating stations is cured before the workpiece is discharged from the decorating machine.
2. Description of the Prior Art
As shown in U.S. Pat. Nos. 2,231,535; 2,261,255; 2,721,516; and 3,146,705 intermittent motion type decorating machines are known in the art and provide a drive system to impart intermittent traveling motion to the workpieces such as containers made of glass or plastic. A container is moved through a predetermined distance, stopped, moved again through a predetermined distance, stopped and again moved until each container through the sequence of motions moves completely through the decorating stations of the machine. A decorating station will be provided at one or more places where the container comes to a stop. At each decorating station, a decorating screen is displaced into line contact with the surface of the container by an associate squeegee. During the decorating process a synchronous speed relation is maintained at line contact established by the squeegee between the screen undergoing linear displacement and the container undergoing rotation. The squeegee remains stationary during the decorating process. Decorating machines of this type are particularly useful to decorate bottles and carryout the decoration while the surface of the bottle to be decorated is horizontally orientated. In the aforesaid U.S. Pat. No. 2,261,255 there is disclosed a drive for moving each of a screen to decorate a cylindrical body of a bottle and a shoulder screen to decorate a tapered neck portion of the bottle substantially at the same peripheral linear speed. The decorating machine disclosed in the aforesaid patent number 3,251,298, provided a production rate of about 125 bottles per minute. More recently as disclosed in U.S. Pat. No. 5,524,535 a decorating machine design is provided to increase the production rate of up to 150 bottles per minute.
In such intermittent motion decorating machines, thermosetting ink was used as a printing medium particularly when multiple color decoration was desired. Ink of only one color is applied at each decorating station and to decorate with multiple colors requires corresponding multiple decoration stations. Because the different colors interleave in a given area of the bottle such an area is contacted with the screens for each color, it is necessary that the ink/color is a solid and will not smear. Although the ink is solidified after each printing operation, it was necessary to cure the ink by feeding the bottles through a furnace after discharging from the decorating machine. The curing of the ink in this way represents an added cost to the printing process in terms of the cost of energy and floor space. Also, the required handling of the bottles was a loss factor because of breakage. The present invention seeks to provide a decorating method and apparatus to allow curing of ink decoration applied at one station before additional decoration is applied so that a bottle delivered from a decoration machine can be loaded directly into shipping containers without the need for curing the ink decoration.
The present invention provides a method and apparatus to use a decorating medium which will cure very rapidly when exposed to a source of an electromagnetic wave such as ultraviolet radiation or heat in intermittent motion type decorating machines discussed hereinbefore, more particularly the present invention provides curing stations which can be interleaved between printing stations and provide drives to rotate the workpiece at the curing station for exposing uncured printing medium to the electromagnetic wave or heat to curing the printing medium. In this way, the workpiece can immediately receive decorating medium applied over the same area containing the cured decorating medium and without the loss of a preestablished orientation such as bottle seam registration.